SBH25 Amorphous-Alloy Oil-Immersed Transformer

Overview

Beyond the energy, material and noise savings of the three-dimensional wound-core design, the oil-immersed amorphous-alloy wound core eliminates the fragmentation problems of conventional amorphous cores, lowers the noise level and improves short-circuit withstand while keeping the very low no-load loss typical of amorphous alloy.

Technical features

• Low no-load loss: hysteresis and eddy-current losses in amorphous alloy are small, so no-load loss is only about 1/3 to 1/4 of a comparable S13 silicon-steel unit — a clear saving at light load and during night-time operation.
• Fully sealed and maintenance-free: the corrugated tank is welded shut, the insulating oil never contacts air, there is no oil-level gauge to maintain and the unit resists moisture and pollution.
• Ageing-resistant core: the physical properties of amorphous alloy are stable, so no-load loss barely drifts over years of service, whereas silicon-steel laminations degrade with age.
• Low noise: low magnetostriction gives roughly 5–10 dB(A) less noise than a silicon-steel oil-immersed unit of the same rating.
• Interference immunity and long life: the closed three-dimensional wound-core construction gives strong immunity to harmonics, stable behaviour under short-circuit stress, low noise and a long service life.

Core material and cooling

The core is wound from amorphous alloy strip produced by rapid quenching: the metal atoms are in a disordered arrangement, which makes the material easier to magnetise and far less lossy than silicon steel. As in any oil-immersed transformer, the oil serves as both insulation and cooling medium, absorbing and carrying away the heat generated in service.